Allison Transmission Serial Number Lookup Jun 2026

If you own a heavy-duty truck and a Nexiq USB-Link, you likely have Allison DOC.

If you are looking up information because of a fault, you can often retrieve directly from the cab: Turn the ignition to ON (engine off). Allison Transmission Serial Number Lookup

The serial number had just exposed a lie. The transmission was original, not rebuilt. Marco walked away from the deal. If you own a heavy-duty truck and a

On many modern Allison transmissions (like the 1000/2000 series found in Chevy/GMC Duramax trucks), you don't need to crawl under the truck. The transmission was original, not rebuilt

Do not confuse the Serial Number with the Model Number. The Model Number tells you the family of the transmission; the Serial Number identifies the individual unit .

: Use the Allison Warranty Tool to see if your unit is still under coverage or has registered Extended Coverage (EC).

The serial number typically consists of and is usually listed directly below the model number on the data plate. Leading digits often indicate the transmission series: 1000/2000 Series : Starts with 631, 632, or 9308. 3000 Series : Starts with 651, 652, or 9307. 4000 Series : Starts with 661, 662, or 943. AT500/1500 Series : Starts with 321 or 9108. MT600 Series : Starts with 241 or 242. HT/CT 700 Series : Generally starts with 251. 3. How to Perform a Lookup